/* * Copyright (c) 2014, Oracle America, Inc. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * * Neither the name of Oracle nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF * THE POSSIBILITY OF SUCH DAMAGE. */ package org.openjdk.jmh.samples; import org.openjdk.jmh.annotations.Benchmark; import org.openjdk.jmh.annotations.BenchmarkMode; import org.openjdk.jmh.annotations.Group; import org.openjdk.jmh.annotations.GroupThreads; import org.openjdk.jmh.annotations.Mode; import org.openjdk.jmh.annotations.OutputTimeUnit; import org.openjdk.jmh.annotations.Scope; import org.openjdk.jmh.annotations.Setup; import org.openjdk.jmh.annotations.State; import org.openjdk.jmh.runner.Runner; import org.openjdk.jmh.runner.RunnerException; import org.openjdk.jmh.runner.options.Options; import org.openjdk.jmh.runner.options.OptionsBuilder; import java.util.concurrent.TimeUnit; import java.util.concurrent.atomic.AtomicInteger; @State(Scope.Group) @BenchmarkMode(Mode.AverageTime) @OutputTimeUnit(TimeUnit.NANOSECONDS) public class JMHSample_15_Asymmetric { /* * So far all the tests were symmetric: the same code was executed in all the threads. * At times, you need the asymmetric test. JMH provides this with the notion of @Group, * which can bind several methods together, and all the threads are distributed among * the test methods. * * Each execution group contains of one or more threads. Each thread within a particular * execution group executes one of @Group-annotated @Benchmark methods. Multiple execution * groups may participate in the run. The total thread count in the run is rounded to the * execution group size, which will only allow the full execution groups. * * Note that two state scopes: Scope.Benchmark and Scope.Thread are not covering all * the use cases here -- you either share everything in the state, or share nothing. * To break this, we have the middle ground Scope.Group, which marks the state to be * shared within the execution group, but not among the execution groups. * * Putting this all together, the example below means: * a) define the execution group "g", with 3 threads executing inc(), and 1 thread * executing get(), 4 threads per group in total; * b) if we run this test case with 4 threads, then we will have a single execution * group. Generally, running with 4*N threads will create N execution groups, etc.; * c) each execution group has one @State instance to share: that is, execution groups * share the counter within the group, but not across the groups. */ private AtomicInteger counter; @Setup public void up() { counter = new AtomicInteger(); } @Benchmark @Group("g") @GroupThreads(3) public int inc() { return counter.incrementAndGet(); } @Benchmark @Group("g") @GroupThreads(1) public int get() { return counter.get(); } /* * ============================== HOW TO RUN THIS TEST: ==================================== * * You will have the distinct metrics for inc() and get() from this run. * * You can run this test: * * a) Via the command line: * $ mvn clean install * $ java -jar target/benchmarks.jar JMHSample_15 -wi 5 -i 5 -f 1 * (we requested 5 warmup/measurement iterations, single fork) * * b) Via the Java API: * (see the JMH homepage for possible caveats when running from IDE: * http://openjdk.java.net/projects/code-tools/jmh/) */ public static void main(String[] args) throws RunnerException { Options opt = new OptionsBuilder() .include(JMHSample_15_Asymmetric.class.getSimpleName()) .warmupIterations(5) .measurementIterations(5) .forks(1) .build(); new Runner(opt).run(); } }